A series of RANS-based aerodynamic shape optimization for an 800-passenger blended-wing-body aircraft is performed. A gradient-based optimization algorithm and a parallel structured multiblock RANS solver with Spalart–Allmaras turbulence model are used. The derivatives are computed using a discrete adjoint method considering both frozen-turbulence and full-turbulence assumptions. A total of 274...

We have studied oscillation of a pendulum in water using spherical bobs. By measuring the loss in potential energy, we estimate the drag coefficient on the sphere and compare to data from liquid-helium experiments. The drag coefficients compare very favorably illustrating the true scaling behavior of this phenomenon. We also studied the decay of amplitude of the pendulum over time. As observed ...

In the off-equatorial region of Jupiter’s and Saturn’s atmospheres, baroclinic eddies transport angular momentum out of retrograde and into prograde jets. In a statistically steady state, this angular momentum transfer by eddies must be balanced by dissipation, likely produced bymagnetohydrodynamic (MHD) drag in the planetary interior. This paper examines systematically how an idealized represe...

The aim of this study was to assess the effects of 8-weeks of training on active drag in young swimmers of both genders. Eight girls and twelve boys' belonging to the same swimming team and with regular competitive participation in national and regional events for the previous two seasons participated in this study. Active drag measurements were conducted in two different evaluation moments: at...

α angle of attack, rad Γ circulation, m2s−1 λ wake wavelength, m ρ∞ free-stream air density, kgm −3 τ panel tangential vector ω angular velocity, rad s−1 a non-dimensional distance between aerofoil mid-chord and centre of rotation A panel area, m b semi-chord, m ∆b panel span, m B wingspan, m c aerofoil chord, m ∆c panel chord, m C Theodorsen’s function, C(k) = F (k) + iG(k) Cd sectional drag c...

Asynchronous Parallel Evolutionary Algorithms (HAPEAs) have shown to be robust as they require no derivatives or gradients of the objective function, have the capability of finding globally optimum solutions amongst many local optima, can be executed asynchronously in parallel and adapted easily to arbitrary solver codes without major modifications. The application of the methodology is illustr...

We study here the motion of a spherical gas bubble in a solid body rotating flow of clean silicon oil, to avoid contamination of interface. From the measurement of its equilibrium position, lift and drag forces are determined. Five different silicon oils have been used, providing five different viscosities and Morton numbers. For spherical bubbles the drag coefficient is at first order the same...

in this study, a pellet scale model was developed for trickle bed reactor utilizing cfd techniques. drag coefficients were calculated numerically at different velocities and bulk porosities in the case of single phase flow through the dry bed. the simulation results were then compared with the prediction of kozeny-carman (k-c) equation. the results indicated that drag coefficients calculated fr...

The flow behavior around a cam shaped tube in cross flow has been investigated experimentally using flow visualization and pressure distribution measurement. The range of attack angle and Reynolds number based on an equivalent circular diameter are within 0 ≤ α ≤ 360˚ and 2 x 104 < Reeq < 3.4 x 104, respectively. The pressure drag features are clarified in relation to the flow behavior around t...

a knowledge of physical and aerodynamic properties of agricultural crops is important and essentially required for the design and development of a crop&apos;s harvesting and post-harvesting equipments. in the present research, experiments were conducted to determine physical and aerodynamic properties of fars province pinto bean namely: kernel size and shape (length, width, thickness, projected...